Automatic tracking device



w. ouPRE. AUTOMATIC TRACKING DEVICE. APPLICATION FILED APIILI. 7H8.

latented July 5, 1921.

Inventor a Fm 92 4 UNITED STATES PATENT OFFICE.

WILFRED DUPRE, 0F WORCESTER, MASSACHUSETTS, ASSIGNOR OF ONE-HALF TO FREDERICK A. MOORE, O1 FOXBORO, MASSACHUSETTS.

AUTOMATIC TRACKING DEVICE.

Application filed April 1,

T0 aZZw/tom z t may concern:

Be it known that I, W'rnrnno Duran, a citizen of the United States, residing at Worcester, in the county of Worcester and Commonwealth of Massachusetts, have invented a new and useful Improvement in Automatic Tracking Devices, of which the following, together with the accompanying drawings, is a specification.

The present invention relates to automatic musical instruments, and particularly to pneumatic piano players, wherein a traveling sheet or web, having perforations corresponding to the notes to be played, isemployedin connection with a tracker bar having a series of apertures each pneumatically connected .to operate one of the hammers of the piano. The present invention relates to .a mechanism for automatically maintaining a correct tracking relation between the traveling note sheet and the apertured tracker bar, so that the accurate registration of every notesheet perforation with its corresponding tracker bar aperture is insured during the playing of a given selection.

Many prior tracking control mechanisms for correcting the deflections and aberrations of the traveling note sheet have been characterized by a, profusion of complicated and delicate pneumatically operated parts, including in most cases a plurality of motor bellows and a plurality of valves associated with each, the operation of which. isdependent upon and responsive to the deflection of the edges of the sheet from trackerbar apertures so located as to be in operative relation to said edges. The objection to such prior devices, in.addition to their extreme complication, is found in the length of time required to actually correct a deflection of the sheet, due to the interposition of so many instrumentalities, all pneumatically operated, betweenthe place wherethe'aberration or deflection occurs andpthe force. which is ultimately applied to correct the same,

The present invention aims to overcome these vital objections to previous mechanisms of this class, by eliminating entirely all pneumatic or suction I operated devices, valves and motor bellows, thereby simplify ing and reducing the cost of the tracking control mechanism, and by substituting for the non-positive and uncertain operation of such prior mechanisms, a positive and accu rate operation which is performed Wholly Specification of Letters Patent.

Patented July 5, 1921. 1918. Serial No. 225,986.

and entirely'by mechanical means, as distinguished from the pneumatic means employed in the devices of the prior art. The operation of correcting the travel of the note sheet is thus made instantly and positively responsive to the deflection thereof,

and this without any reliance whatsoever on pneumatically operated devices with their attendant difficulty of adjustment, and their liability to get out of order. My invention is fully set forth in the following description and pointed out in the annexed claims, reference being had to the accompanyingdrawings, in whichi I Figure 1 is a front view of the mechanism embodying the invention.

Fig 2 isja fragmentary sectional view on the line 2-2 of Fig. 1.

F ig; 3 is a fragmentary sectional view on 1ajplane transverse to the shaft 19 and tracker ar 5. r

Fig. lis a detail sectional view of a portion of the mechanically operated member which responds tothe position of, the note sheet, as hereinafter described, and

Fig. 5 is a detail sectional view of one end of the main'drivingshaft of the mechanism, as hereinafter described,

Like reference characters refer to like partsin the different figures.

As shown in Fig. 1, an ordinary framework 1 provides for the support of theusual delivering music spool 2 and the usual receiving music spool 3. During the opera tion of playing a selection from the perforated note sheet 4,, contained on the spool 2, said sheet is drawnacross the face of an apertured tracker bar 5, by power applied to the. shaft of receiving spool 3 from amain driving shaft 6, which is constantly rotated, as by a sprocket chain connection, 7 from the driving motor of the instrument. The supply or delivery spool2. on which the sheet 4 is rolled is insert-ible in the usual manner by the retraction of a spring pressed spindle 8-, whereby the clutching of said spool with the end of a driving spindle 9 is accomplished.

The driving spindle 9 carries a sprocket 10which is connected by a sprocket chain 11 with a sprocket 12, normally running loose on the main driving shaft 6. Said main driving, shaft 6 has secured thereto a sliding collar 13 which carries a pinion 14, adapted in the position shown in Fig. l to mesh with a gear 15 on the shaft of receiving spool 3, and thereby to drive said receiving spool 1n the proper direction to draw the note sheet downward across the tracker bar 5. The collar 13 is subject to the operation of a reversing lever 16, by means of which the shaft 6 is moved to the right, Fig. 1, so as to disengage the pinion 1& from the gear 15, and to clutch together the shaft 6 and the loose sprocket 12 thereon, by means of coacting clutch teeth or pins 17 17, or the like. Thus the receiving spool 3 is freed from the driving power and the supply spool 2 is positively connected to the shaft 6, for the rewinding of the note sheet after the playing thereof has been completed.

The tracker bar 5, as shown in Fig. 1, terminates short of the framework 1 at each end, and is mounted for longitudinal sliding movement on guide pins 18, 1.8 projecting inwardly from the framework and received within suitable guide recesses in said tracker bar, which recesses are longer and deeper than the pins, so that the tracker bar can be moved in either direction. The tracker bar 5 thus becomes, in the illustrated embodiment of my invention, the member which is movable in one direction or the other to correct any deflection of the note sheet perforations from the corresponding tracker bar apertures, but it is to be understood that my invention is not limited in this respect. In any case however, whether the tracker bar be moved or the sheet be moved, this movement is accomplished by purely mechanical means, and in the illustrated embodiment of my invention this means comprises in part a rotatable shaft 19 which is journaled in the framework 1,

parallel to the spools 2, 3 and to the tracker bar 5. Said shaft 19 is adapted to slide freely longitudinally in its journals, and carries on one end a sprocket 20 which is connected by a sprocket chain 21 to a sprocket 22 running loose on the shaft of receiving spool 3. During the playing op eration of a note sheet when said receiving spool is operatively connected to main shaft 6, as shown in Fig. 1, the sprocket 22 is clutched to the shaft of said spool by the engagement of clutch teeth or pins 23 and 24, one on said sprocket and the other on a collar 25 secured to said shaft. Thus, during the playing of a note sheet, the slidable shaft 19 is continuously rotated.

At each end of shaft 19 is secured a disk 26, and on the outer face of each disk 26 are formed a series of suitably spaced teeth 27. Associated with each disk 26 is an adjustable collar 28, which is threaded, as shown in Fig. 4:, so as to be capable of limited adjustment toward and away from the inner face of its disk 26. The inner face of each disk 26 may be suitably graduated, as shown in Fig. 2, and each collar 28 may carry a dial or pointer 29, so that great accuracy may be secured in fixing these collars in position to project exactly the same distance inwardly from the disks 26. Bearing against the inner end of each collar 28 is a member 30, having an outwardly turned flange 31 thereon which is in position to make contact with the corresponding edge of the traveling note sheet 4. The members 30 are loosely slidable on the shaft 19, and are prevented from turning thereon by inturned flanges 32 thereof, which are engaged by pins 33 projecting upwardly from the tracker bar. WVhen the collars are properly adjusted, and the members 30 are in position thereagainst, the space between the flanges 31 is just equal to the width of the traveling note sheet, and if the latter is tracking properly, with its perforations in correct registration with the corresponding tracker bar apertures, there is, obviously,

no tendency for either edge of the sheet" to bear unduly against the flanges 31; as a consequence, no longitudinal movement is imparted to the shaft 19, which simply rotates freely, under these conditions, since the teeth 27 of disks 26 are not in a position to engage with any cooperating mecha- IllSIIl.

When, however, there is any deviation of the note sheet from its correct tracking relation, this deviation is communicated through either one of the members 30 to move the shaft 19 longitudinally in its bearings, by the thrust of one edge 01' the other i of the sheet against the corresponding flange 31. This longitudinal movement of shaft 19 carries the teeth 27 of one or the other disk 26 into a position to operatively engage certain devices adapted to communicate motion to the tracker bar 5, in a direction to correct the deviation. As herein shown, each end of the tracker bar has ournaled therein a vertical spindle 34, carrying on its upper end a toothed or ratchet wheel 35. The two ratchet wheels 35, 35 are so disposed that in the normal tracking relation of the note sheet, their teeth just escape contact with the teeth 27 of the adjacent disks 26. Each spindle 34 also carries a pinion 36 which is in mesh with a gear 37, Figs. 2 and 3, on a second vertical spindle 38, journaled in a bearing bracket 39 extending rearwardly from the tracker bar. Each spindle 33 carries a pinion 40 which is in mesh with the teeth of a stationary rack 4L1, projecting inwardly from the framework 1.

There is no rotation imparted to any of the spindles 3 1, 3% and 38, 38 when the sheet is tracking normally, in correct registration, since as before stated, the rotating shaft 19 is held in neutral position, that is, with the toothed disks 26 just removed from contact with the ratchet wheels 35. A slight lateral deflection of the note sheetto the right in Fig. 1 is answered instantly however, by the engagement of a tooth of right hand disk 26.swith the corresponding ratc Wheel 35, and thus through the gearing 36, 37 and 40, 41 the tracker bar is movedin the. same direction to compensate for this deflection. The'movement of the tracker bar automatically restores the entire -mecha- .nism-to normal tracking relation, since'this deflection occurs. Also, it is to be noted that the correcting force is exerted at the precise point of error or aberration in the operation of the device; in other words, the error is corrected immediately at its source, as distinguished from the prior devices of this. class, operating on the pneumatic principle,

where it is attempted to correct the. position of only that portion of "the note; sheet which follows the portion in which the error occurs.

It remains only to show the manner in which the mechanical correction instrumentalities. are rendered inoperative upon the rewinding of the note sheet 4. For this purpose the end of main shaft 6 is providedwith a telescoping member 42, as shown in Fig. 5, which has a lost motion connection with said shaft, by mea'ns of a projection 43 working in an elongated slot 44 of said shaft. The member 42 passes through a lever 45, pivoted at 46 to the framework 1, said member 42 carrying check nuts 47, 47 on opposite sides of said lever, with the inner check nut adapted to contact with the end of shaft 6. The free end of lever 45 is bifurcated to engage a groove 48 in the hub of sprocket 22, which, as before stated, is loose on the shaft of spool 3. In the normal operating position ofthe parts, during the playing of a selection, the shaft 6 is in the position shown in Figs. 1 and 5, and in this position holds the lever 45 toward the left, and thus secures the clutching of the sprocket 22 to the fixed collar 25. When the reversing lever 16 is thrown to the right, so as to begin the rewinding of the note sheet, as heretofore described, the final part of this movement draws the outer end of slot 44 against the projection 43, and thus pulls the lever 45 inwardly a sufficient distance to separate the clutch teeth or pins 23 and 24. Therefore, on the rewinding of the note sheet, the shaft 19 is idle, since its driving connection from the shaft of spool 3 is broken. This driving connection is restored as soon asthe lever 16 is shifted back a ain tothe position shown inFig. 1 for the p ay ing of another selection.

I claim, Y 1. The. combination with a tracking. device for a perforated traveling musicsheetand a tracker bar, of means for controlling the lateral deflection of the music sheet as it is moved over the tracker bar, comprising a rotatable shaft extending lengthwise the tracker bar and parallel therewith, means for rotating, said shaft during the playing of apiece, means actuated by the lateral deflection of the music sheet for imparting a longitudinal movement to saidshaft, and means actuated by the rotation of said'shaft for restoring the normal relation, of the music sheet and the tracker bar.

2. .The combination with a perforated music sheet, a tracker bar and means for moving the music sheet over the tracker bar during the playing of a piece, of means for maintainingthe normal relation of the music sheet and the tracker bar, comprising. a rotatable shaft. extending lengthwise the tracker bar and parallel therewith, means for rotating said, shaft during the playing'of; a piece, means actuated by the lateral -de-' fiection of the music sheet from its normal path for imparting a longitudinal move ment to said shaft, and means actuated by the rotation of said shaft for imparting a longitudinal movement to the tracker bar to restore the, normal relation of the tracker bar and music sheet.

3.-In an automatic-tracking device for a perforated music sheet, the combination'with a tracker bar. capable of a longitudinal movement and means for moving the music sheet over the tracker bar during the playing of a piece, of." means for maintaining the, normal relation of the tracker bar and music sheet, comprising a shaft extendinglengthwise the tracker bar andparallel therewith, means for rotating said shaft during the playing of a piece, means forimparting a longitudinal movement to said shaft by the deflection of the music sheet from'its normal path, a pair of tootheddisks attached to said shaft near its. ends, mechanism for imparting a longitudinal movement to the tracker bar normally out of engagement with said toothed disks, and means actuated by the deflection of the music sheet for imparting a longitudinal movement to said rotatable shaft to bring one or the other of said toothed disks into engagement with said tracker bar moving mechanism.

4. In an automatic tracking device for a perforated music sheet, the combination with a tracker bar and means formoving the music sheet over the tracker bar, of means for maintaining the normal relation of the tracker bar and the music sheet, comprising a rotatable shaft extending lengthwise the tracker bar, journaled in bearings parallel with the tracker bar and capable of a longitudinal movement in its bearings, means actuated by the lateral deflection of the music sheet for imparting a longitudinal movement to said shaft, means for rotating said shaft during the playing of a piece, and means actuated by the rotation of said shaft for imparting a longitudinal movement to said tracker bar, consisting of a pair of disks carried by said shaft near its ends, arranged to be carried into engagement alternately with the tracker bar moving mechanism as the music sheet is deflected from its normal path.

5. In an automatic tracking device for a perforated music sheet, the combination with a tracker bar capable of a longitudinal movement, of a fixed rack, a pinion carried by the tracker bar and engaging said rack, and means actuated by the lateral deflection of the music sheet for rotating said pinion, comprising a rotatable shaft extending lengthwise the tracker bar and parallel therewith, members contacting directly with the edges of the music sheet to move said shaft longitudinally as the music sheet is deflected from its normal path, toothed disks attached to said shaft, an adjustable collar between said contacting members and said shaft, and means actuated "by said toothed disks to rotate the pinion carried by the tracker bar.

6. In an automatic tracking device for a perforated music sheet, a tracker bar capable of longitudinal movement, a shaft parallel with, and j ournaled independently of the tracker bar, means for continuously rotating said shaft during the playing of a piece, a pair of oppositely disposed toothed disks attached to said shaft, a pair of fixed racks parallel with the ends of the tracker bar, rotative mechanism carried by the tracker bar engaging said racks, and means actuated by lateral deflection of the music sheet for imparting an endwise movement to said shaft to carry one or the other of its toothed disks into engagement with the rotative mechanism carried by the tracker bar.

7 In a mechanism of the class described,

a pair of music spools, a tracker bar mounted between said spools and capable of longi tudinal' movement, means for rotating one of said spools to move the music sheet over the tracker bar, a shaft parallel with the tracker bar, an operative connection between a rotating music spool and said shaft, whereby said shaft is continuously rotated during the playing of a piece, means actuated by said rotating shaft for imparting a longitudinal movement to said tracker bar, and means actuated by the lateral deflection of the music sheet for establishing an operative connection between said rotating shaft and the tracker bar moving mechanism.

8. In a mechanism of the class described, a tracker bar capable of longitudinal movement, a pair of music spools, means for rotating one of said spools to move a music sheet over the tracker bar, a shaft parallel with the tracker bar, means for operatively connecting the rotating music spool with said shaft, comprising a clutching mechanism, whereby the shaft is continuously rotated during the playing of a piece, means for disconnecting said clutching mechanism during the reverse movement of the music sheet, means for imparting a longitudinal movement to the tracker bar, and means actuated by the lateral deflection of the music sheet for operatively connecting said rotating shaft with the tracker bar moving mechanism.

9. In a mechanism of the class described, a tracker bar capable of longitudinal movement, a shaft parallel with the tracker bar, means for continuously rotating said shaft during the playing of a piece,- a pair of toothed disks attached to said shaft, means carried by the tracker bar for imparting a rotative movement thereto, members contacting with the edge of the music sheet for imparting an endwise movement to said shaft to carry one or theother of said disks into operative connection with the tracker bar moving mechanism, and means for adjusting the space between said disks and said contacting members.

WILFRED DUPRE. Witnesses:

NELLIE WHALEN, GEO. H. KENNEn 'Jr. 

